Caller went to my voice mail system, didn't leave a message but I could hear noise in the background

Got a call from this number and did not answer....they left no message but could hear alot of noise in the background....recalled the number and no answer......

This number called me claiming I won a vacation

number has called me several times and claims that i have won a vacation

unknown caller keeps calling gets into my message center and leaves no message and when i answer no says anything on the other end